Any drug developers looking to push a late-stage program for lupus may want to pay close attention to a new note from Citi analyst Yaron Werber covering some unexpected problems for Human Genome Sciences' ($HGSI) Benlysta.

With no real options to replace the first new lupus drug in a half century, doctors are content to prescribe it for now, says the analyst. But they aren't very enthusiastic about the drug's benefits and will be easily persuaded to switch to a new entry from a developer who studies the Benlysta research and learns how to produce better results from better designed studies.

"While docs are happy that Benlysta is now available, they are clearly looking for better options down the line," Werber said, according to the AP story.

The analyst lowered his sales estimates for later in the year, along with his projected price for HGS stock. But that didn't seem to scare off any of the company's investors as its shares hovered around $13.45, up a bit.